There is an conventionally known fluctuation attenuator which transmits the driving force output from the internal combustion engine to a transmission, and simultaneously, attenuates the fluctuation of the driving force of the internal combustion engine (for example, see Japanese Laid-open Patent Publication No. 2015-86965).
The fluctuation attenuator has a first flywheel connected to an internal combustion engine, a housing portion provided on the first flywheel, a second flywheel connected to the transmission so as to enable the relative angular displacement around the same axis relative to the first flywheel, a plurality of spring sheets inserted into the housing portion so as to be slidable to the circumferential direction, and a coil spring held on the spring sheet such that the both ends of the coil spring contact on the spring sheet in a non-transmission state. An inserting hole into which the coil spring is inserted is provided on the spring sheet.